I am new to iOS Programming and I have downloaded the google maps sdk for iOS and followed the instruction on their website ( as shown in this link https://developers.google.com
Make your view normally with InterfaceBuilder and to put mapView at 0 index subview :
mapView_ = [GMSMapView mapWithFrame:self.view.bounds camera:camera];
mapView_.myLocationEnabled = YES;
[self.view insertSubview:mapView_ atIndex:0];
Thanks to Raul Clauss from this thread
And you can custom the size of mapView, change :
mapView_ = [GMSMapView mapWithFrame:_mapHolder.bounds camera:camera];
mapView_.myLocationEnabled = YES;
[_mapHolder insertSubview:mapView_ atIndex:0];
Where mapHolder, is a UIView made inside the IB.